This study as part of the GCRC is to better understand the IgE-mediated mechansisms of food allergies and, in particular, of food-induced atopic dermatitis. We have obtained blood donations from subject, of which one was food - challenged as part of the protocol. As part of our investigation, we became particularily interested in the role that lectin flycoproteins, such as peanut agglutinin (PNA), may have in the development of food allergies such as peanut allergy. We have been able to define specific conditions that upregulate PNA binding by lymphyocytes. We are currently refining our understanding of these conditions, in order to determine if PNA can co-stimulate B lymphycyte differnatation to induce cytokine secreation and/or IgE synthesis. An abstract of this work has been accepted for presentation at the 1999 AAAAI Annual Meeting. If these studies continue to be promising, then we will continue this protocol to determine if subjects with atopic dermatitis may be predisposed to co-stimulation of IgE production by PNA.